I don't like buying from a carrier as I quite frequently travel between Denmark (where I use TDC) and Sweden (where I use Halebop).
So I always buy my phones without any plan and from a generic phone store (or, from the manufacturer's website).
Oh, okay, so you're in EU, all phones are open game.
In all honesty, the phone I've always been most satisfied with was the iPhone. I don't care much for bootloaders and stuff, all my apps are legit, etc, so I don't mind the fact that its closed off.
But the phone I've loved the most since I've had phones?
The Motorola Razr. Classic gray one. That bitch was sweet.